1. Field of the Invention
The present invention relates generally to cooling of electronic components in electronic devices. More particularly, the present invention relates to a heat sink structure, which utilizes a cabinet of an electronic device.
2. Description of the Related Art
As the art moves towards higher power integrated circuits and components, hereinafter referred to as heat emitting components, heat transfer from the heat emitting components becomes increasingly difficult and more important. One conventional technique to remove heat from a heat emitting component was to employ a finned heat sink which was placed in thermal contact with the heat emitting component. In this manner, heat generated by the heat emitting component was conducted to the heat sink and then dissipated to the ambient environment.
Hassanzadeh et al., U.S. Pat. No. 5,761,041, which is herein incorporated by reference in its entirety, teaches a finned heat sink which was placed in thermal contact with a heat emitting component. To mount the heat sink, a bolster plate was positioned below a printed circuit board, and two pins extended up from the bolster plate, through the printed circuit board and through the base of the heat sink. A spring, engaged with the two pins, pressed the heat sink into thermal contact with the heat emitting component.
Although the heat sink of Hassanzadeh et al. was suitable for its intended purpose, in some applications, there was only limited space for the heat sink. In these applications, the size of the heat sink, which could be placed in the limited space, was not adequate to sufficiently cool the heat emitting component. To enhance heat transfer from the heat emitting component and heat sink in this event, additional and/or more powerful fans were often used. However, to avoid excess power consumption and to avoid exceeding noise level limits, the size of these additional and/or more powerful fans was severely restricted.
Accordingly, the art needs a method of enhancing heat transfer from a heat emitting component where there is only limited space for a heat sink and without providing additional and/or more powerful fans.
In accordance with the present invention, a heat sink structure includes a heat emitting component, an inner heat sink in thermal contact with the heat emitting component, a cabinet of a computer system in thermal contact with the inner heat sink, and an outer heat sink in thermal contact with the cabinet.
The cabinet defines an outer region outside of the computer system and an inner region inside of the computer system. Generally, the outer region is cooler than the inner region. Advantageously, since the outer heat sink is located in the outer region, the outer heat sink is relatively cool compared to the heat emitting component. This drives heat from the heat emitting component through the inner heat sink and the cabinet to the outer heat sink, which dissipates this heat to the outer region outside of the computer system.
In one particular embodiment, a heat sink structure includes an inner heat sink having a first heat transfer surface, a cabinet, and a second heat sink having an end plate, which includes a second heat transfer surface. A first screw passes through a first aperture in the cabinet and is threaded into a first threaded aperture in the first heat transfer surface of the inner heat sink. Similarly, a second screw passes through a second aperture in the cabinet and is threaded into a second threaded aperture in the first heat transfer surface of the inner heat sink. In this manner, the inner heat sink is mounted to the cabinet.
Heads of the first and second screws protrude into cavities in the outer heat sink. In this manner, the outer heat sink provides clearance for the heads of the first and second screws.
A third screw passes through a first aperture in the outer heat sink, through a third aperture in the cabinet and is threaded into a third threaded aperture in the inner heat sink. Similarly, a fourth screw passes through a second aperture in the outer heat sink, through a fourth aperture in the cabinet and is threaded into a fourth threaded aperture in the inner heat sink. In this manner, the outer heat sink is mounted to the cabinet.
Also in accordance with the present invention, a method includes thermally connecting an inner heat sink to a heat emitting component. The inner heat sink is thermally connected through a cabinet to an outer heat sink. The heat emitting component generates heat and this heat is conducted to the inner heat sink, to the cabinet, and to the outer heat sink, which dissipates the heat to the outer region outside of the computer system.
These and other features and advantages of the present invention will be more readily apparent from the detailed description set forth below taken in conjunction with the accompanying drawings.